Add process polyfill for mobile compatibility

[gvivster]

Fixes #10 Making it function on a mobile device
(at least for Android, not tested on iOS - if someone with an iOS device could let me know if it works, I'd appreciate it.)

@lukasbach

Problem

Plugin wasn't working on mobile - it would fail to activate with this error:

(It WOULD work on the emulated version on desktop, which made it more confusing.)
Apparently it couldn't find the process object.
Added a process polyfill to fix this.

Changes

• Created process-polyfill.ts to provide the basic environment stuff React needs
• Added import for the polyfill in main.ts

Testing

Got it working on my Android Note S9! The plugin now:

• Activates properly
• Shows up in the menu
• Lets me reorder files just like on desktop

It's finally perfect for my Android needs! (happy dance) Let me know if you need me to test anything else!